/*
    Copyright 2005-2012 Intel Corporation.  All Rights Reserved.

    This file is part of Threading Building Blocks.

    Threading Building Blocks is free software; you can redistribute it
    and/or modify it under the terms of the GNU General Public License
    version 2 as published by the Free Software Foundation.

    Threading Building Blocks is distributed in the hope that it will be
    useful, but WITHOUT ANY WARRANTY; without even the implied warranty
    of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with Threading Building Blocks; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    As a special exception, you may use this file as part of a free software
    library without restriction.  Specifically, if other files instantiate
    templates or use macros or inline functions from this file, or you compile
    this file and link it with other files to produce an executable, this
    file does not by itself cause the resulting executable to be covered by
    the GNU General Public License.  This exception does not however
    invalidate any other reasons why the executable file might be covered by
    the GNU General Public License.
*/

#if _MSC_VER
    // Suppress "decorated name length exceeded, name was truncated" warning
    #pragma warning (disable: 4503)
#endif

#include "tbb/flow_graph.h"
#include "tbb/task_scheduler_init.h"
#include "tbb/tick_count.h"
#include "tbb/atomic.h"
#include "tbb/spin_mutex.h"
#include <iostream>
#include "../../../common/utility/utility.h"
#include <cstdlib>
#include <cstdio>

#if _WIN32 || _WIN64
#include "windows.h"
#define SLEEP(a) Sleep(a*1000)
#else
#define SLEEP(a) sleep(a)
#endif

// Each philosopher is an object, and is invoked in the think() function_node, the
// eat() function_node and forward() multifunction_node.
//
// The graph is constructed, and each think() function_node is started with a continue_msg.
//
// The philosopher will think, then gather two chopsticks, eat, place the chopsticks back,
// and if they have not completed the required number of cycles, will start to think() again
// by sending a continue_msg to their corresponding think() function_node.
//
// The reserving join has as its inputs the left and right chopstick queues an a queue
// that stores the continue_msg emitted by the function_node after think()ing is done.
// When all three inputs are available, a tuple of the inputs will be forwarded to the
// eat() function_node.  The output of the eat() function_node is sent to the forward()
// multifunction_node.

const int think_time = 1;
const int eat_time = 1;
const int num_times = 10;

tbb::tick_count t0;
bool verbose = false;

const char *names[] = { "Archimedes", "Bakunin", "Confucius", "Democritus", "Euclid"
                      , "Favorinus", "Geminus", "Heraclitus", "Ichthyas", "Jason of Nysa",
                          "Kant", "Lavrov", "Metrocles", "Nausiphanes", "Onatas", "Phaedrus",
                          "Quillot", "Russell", "Socrates", "Thales", "Udayana",
                          "Vernadsky", "Wittgenstein", "Xenophilus", "Yen Yuan", "Zenodotus"
};
const int NumPhilosophers = sizeof(names) / sizeof(char*);

// from seismic
int get_default_num_threads() {
    static int threads = 0;
    if ( threads == 0 )
        threads = tbb::task_scheduler_init::default_num_threads();
    return threads;
}

struct RunOptions {
    utility::thread_number_range threads;
    int number_of_philosophers;
    bool silent;
    RunOptions(utility::thread_number_range threads_, int number_of_philosophers_, bool silent_) :
        threads(threads_), number_of_philosophers(number_of_philosophers_), silent(silent_) { }
};

RunOptions ParseCommandLine(int argc, char *argv[]) {
    int auto_threads = get_default_num_threads();
    utility::thread_number_range threads(get_default_num_threads, auto_threads, auto_threads);
    int nPhilosophers = 5;
    bool verbose = false;
    char charbuf[100];
    std::sprintf(charbuf, "%d", NumPhilosophers);
    std::string pCount = "how many philosophers, from 2-";
    pCount += charbuf;

    utility::cli_argument_pack cli_pack;
    cli_pack.positional_arg(threads, "n-of_threads", "number of threads to use, a range of the form low[:high], where low and high are non-negative integers or 'auto' for the TBB default.")
            .positional_arg(nPhilosophers, "n-of-philosophers", pCount)
            .arg(verbose,"verbose","verbose output");
    utility::parse_cli_arguments(argc, argv, cli_pack);
    if(nPhilosophers < 2 || nPhilosophers > NumPhilosophers) {
        std::cout << "Number of philosophers (" << nPhilosophers << ") out of range [2:" << NumPhilosophers << "]\n";
        std::cout << cli_pack.usage_string(argv[0]) << std::flush;
        std::exit(1);
    }
    return RunOptions(threads, nPhilosophers,!verbose);
}


tbb::spin_mutex my_mutex;

class chopstick {};

using namespace tbb::flow;

typedef std::tuple<continue_msg, chopstick, chopstick> join_output;
typedef join_node< join_output, reserving > join_node_type;

typedef function_node<continue_msg, continue_msg> think_node_type;
typedef function_node<join_output, continue_msg> eat_node_type;
typedef multifunction_node<continue_msg, join_output> forward_node_type;

class philosopher {
public:

    philosopher( const char *name ) : 
        my_name(name), my_count(num_times) { }

    ~philosopher() {
    }

    void check();
    const char *name() const { return my_name; }

private:

    friend std::ostream& operator<<(std::ostream& o, philosopher const &p);

    const char *my_name;
    int my_count;

    friend class think_node_body;
    friend class eat_node_body;
    friend class forward_node_body;

    void think( );
    void eat();
    void forward( const continue_msg &in, forward_node_type::output_ports_type &out_ports );
};

std::ostream& operator<<(std::ostream& o, philosopher const &p) {
    o << "< philosopher[" << reinterpret_cast<uintptr_t>(const_cast<philosopher *>(&p)) << "] " << p.name() 
        << ", my_count=" << p.my_count;
    return o;
}

class think_node_body {
    philosopher& my_philosopher;
public:
    think_node_body( philosopher &p ) : my_philosopher(p) { }
    think_node_body( const think_node_body &other ) : my_philosopher(other.my_philosopher) { }
    continue_msg operator()( continue_msg /*m*/) {
        my_philosopher.think();
        return continue_msg();
    } 
};

class eat_node_body {
    philosopher &my_philosopher;
public:
    eat_node_body( philosopher &p) : my_philosopher(p) {}
    eat_node_body( const eat_node_body &other ) : my_philosopher(other.my_philosopher) { }
    continue_msg operator()(const join_output &in) {
        my_philosopher.eat();
        return continue_msg();
    }
};

class forward_node_body {
    philosopher &my_philosopher;
public:
    forward_node_body( philosopher &p) : my_philosopher(p) {}
    forward_node_body( const forward_node_body &other ) : my_philosopher(other.my_philosopher) { }
    void operator()( const continue_msg &in, forward_node_type::output_ports_type &out) {
        my_philosopher.forward( in, out);
    }
};

void philosopher::check() {
    if ( my_count != 0 ) {
        std::printf("ERROR: philosopher %s still had to run %d more times\n", name(), my_count);
        std::exit(1);
    }
}

void philosopher::forward( const continue_msg &/*in*/, forward_node_type::output_ports_type &out_ports ) {
    if(my_count < 0) abort();
    --my_count;
    (void)std::get<1>(out_ports).try_put(chopstick());
    (void)std::get<2>(out_ports).try_put(chopstick());
    if (my_count > 0) {
        (void)std::get<0>(out_ports).try_put(continue_msg());  //start thinking again
    } else {
        if(verbose) {
            tbb::spin_mutex::scoped_lock lock(my_mutex);
            std::printf("%s has left the building\n", name());
        }
    }
}

void philosopher::eat() {
    if(verbose) {
        tbb::spin_mutex::scoped_lock lock(my_mutex);
        std::printf("%s eating\n", name());
    }
    SLEEP(eat_time); 
    if(verbose) {
        tbb::spin_mutex::scoped_lock lock(my_mutex);
        std::printf("%s done eating\n", name());
    }
}

void philosopher::think() { 
    if(verbose) {
        tbb::spin_mutex::scoped_lock lock(my_mutex);
        std::printf("%s thinking\n", name());
    }
    SLEEP(think_time); 
    if(verbose) {
        tbb::spin_mutex::scoped_lock lock(my_mutex);
        std::printf("%s done thinking\n", name());
    }
}

typedef queue_node<continue_msg> thinking_done_type;

int main(int argc, char *argv[]) {
    int num_threads;
    int num_philosophers;

    RunOptions options = ParseCommandLine(argc, argv);
    num_philosophers = options.number_of_philosophers;
    verbose = !options.silent;

    for(num_threads = options.threads.first; num_threads <= options.threads.last; ++num_threads) {
    
        tbb::task_scheduler_init init(num_threads);

        graph g;

        if(verbose) std::printf("\n%d philosophers with %d threads\n\n", num_philosophers, num_threads);
        t0 = tbb::tick_count::now();

        std::vector<queue_node<chopstick> > places(num_philosophers, queue_node<chopstick>(g));
        std::vector<philosopher> philosophers;
        philosophers.reserve(num_philosophers);
        std::vector<think_node_type *> think_nodes;
        think_nodes.reserve(num_philosophers);
        std::vector<thinking_done_type> done_vector(num_philosophers, thinking_done_type(g));
        std::vector<join_node_type> join_vector(num_philosophers,join_node_type(g));
        std::vector<eat_node_type *> eat_nodes;
        eat_nodes.reserve(num_philosophers);
        std::vector<forward_node_type *> forward_nodes;
        forward_nodes.reserve(num_philosophers);
        for ( int i = 0; i < num_philosophers; ++i ) {
            places[i].try_put(chopstick());
            philosophers.push_back( philosopher( names[i] ) );  // allowed because of default generated assignment
            if(verbose) {
                tbb::spin_mutex::scoped_lock lock(my_mutex);
                std::cout << "Built philosopher " << philosophers[i] << std::endl;
            }
            think_nodes.push_back(new think_node_type(g, unlimited, think_node_body(philosophers[i])));
            eat_nodes.push_back( new eat_node_type(g, unlimited, eat_node_body(philosophers[i])));
            forward_nodes.push_back( new forward_node_type(g, unlimited, forward_node_body(philosophers[i])));
        }
  
        // attach chopstick buffers and think function_nodes to joins
        for(int i = 0; i < num_philosophers; ++i) {
            think_nodes[i]->register_successor(done_vector[i]);
            done_vector[i].register_successor(input_port<0>(join_vector[i]));
            places[i].register_successor(input_port<1>(join_vector[i])); // left chopstick
            places[(i+1) % num_philosophers].register_successor(input_port<2>(join_vector[i]));  // right chopstick
            // attach join to eat function_node
            join_vector[i].register_successor(*(eat_nodes[i]));
            // attach eat to forward mofn
            make_edge(*(eat_nodes[i]), *(forward_nodes[i]));
            // attach mofn to think function_nodes
            output_port<0>(*(forward_nodes[i])).register_successor(*(think_nodes[i]));
            // attach mofn to chopstick queues
            output_port<1>(*(forward_nodes[i])).register_successor(places[i]);
            output_port<2>(*(forward_nodes[i])).register_successor(places[(i+1) % num_philosophers]);
        }

        // start all the philosophers thinking
        for(int i = 0; i < num_philosophers; ++i) think_nodes[i]->try_put(continue_msg());

        g.wait_for_all();

        tbb::tick_count t1 = tbb::tick_count::now();
        if(verbose) utility::report_elapsed_time((t1-t0).seconds());

        for ( int i = 0; i < num_philosophers; ++i ) philosophers[i].check();

        for(int i = 0; i < num_philosophers; ++i) {
            delete think_nodes[i];
            delete eat_nodes[i];
            delete forward_nodes[i];
        }
    }
    return 0;
}
